An electrolyser is an apparatus where an electrolysis reaction takes place. Electrolysis is the process of decomposing a chemical compound into its elements or producing a new compound by the action of an electrical current. An electrolyser cell is typically composed of two electrodes and a separator, and multiple cells are used to achieve a desired electrolysis process.
A significant reduction in cell current efficiency may be caused by damages to the cell membrane. These damages commonly result from holes caused by voids, blisters and delamination due to faults in startup and shutdown procedures, electrolyte contaminants, or as a consequence of the normal aging process. These damages will, in the end, affect the cell through shortcomings such as significant back-migration of sodium hydroxide in the anode compartment and consequently affect the quality of the produced chlorine (oxygen evolution), and increase the risk of shortcuts between the anode and the cathode, thereby causing structural damages to the cell. Corrosion of the anode due to the imbalanced pressure between the anodic and the cathodic compartment may be another possible shortcoming.
Known methods of measuring electrolyser efficiency involve chemical analysis on a global basis. However, such methods do not allow identification of an individual cell's efficiency. Therefore, there is a need to determine efficiency on a cell-by-cell basis.